Yes, ArtResin epoxy resin can be used over organic material such as butterfly wings, rocks and leaves. The resin will seal it in, protecting it from the air and preserving its natural brilliant color. Be aware that resin can make some items look as they would when wet - test first so you know exactly what to expect. Make sure natural items are thoroughly dried or they may rot under the resin. Some natural objects can off-gas trapped air into the resin in the form of bubbles - you may want to seal first as a precaution. Choose items that are fairly flat so the resin is sure to cover them completely, or you may need to pour multiple coats to cover areas of high relief. Use caution when pouring and spreading over delicate areas of your artwork and be aware that the resin is thick and can be heavy if a large amount is used. Because of this, you may wish to apply the resin in thin coats.